[llvm] r278571 - [Inliner] Don't treat inalloca allocas as static
Reid Kleckner via llvm-commits
llvm-commits at lists.llvm.org
Fri Aug 12 15:23:05 PDT 2016
Author: rnk
Date: Fri Aug 12 17:23:04 2016
New Revision: 278571
URL: http://llvm.org/viewvc/llvm-project?rev=278571&view=rev
Log:
[Inliner] Don't treat inalloca allocas as static
They aren't static, and moving them to the entry block across something
else will only result in tears.
Root cause of http://crbug.com/636558.
Added:
llvm/trunk/test/Transforms/Inline/inalloca-not-static.ll
Modified:
llvm/trunk/lib/Transforms/Utils/InlineFunction.cpp
Modified: llvm/trunk/lib/Transforms/Utils/InlineFunction.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/InlineFunction.cpp?rev=278571&r1=278570&r2=278571&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/InlineFunction.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/InlineFunction.cpp Fri Aug 12 17:23:04 2016
@@ -1294,6 +1294,13 @@ updateInlinedAtInfo(const DebugLoc &DL,
return DebugLoc::get(DL.getLine(), DL.getCol(), DL.getScope(), Last);
}
+/// Return the result of AI->isStaticAlloca() if AI were moved to the entry
+/// block. Allocas used in inalloca calls and allocas of dynamic array size
+/// cannot be static.
+static bool allocaWouldBeStaticInEntry(const AllocaInst *AI ) {
+ return isa<Constant>(AI->getArraySize()) && !AI->isUsedWithInAlloca();
+}
+
/// Update inlined instructions' line numbers to
/// to encode location where these instructions are inlined.
static void fixupLineNumbers(Function *Fn, Function::iterator FI,
@@ -1328,7 +1335,7 @@ static void fixupLineNumbers(Function *F
// Don't update static allocas, as they may get moved later.
if (auto *AI = dyn_cast<AllocaInst>(BI))
- if (isa<Constant>(AI->getArraySize()))
+ if (allocaWouldBeStaticInEntry(AI))
continue;
BI->setDebugLoc(TheCallDL);
@@ -1626,7 +1633,7 @@ bool llvm::InlineFunction(CallSite CS, I
continue;
}
- if (!isa<Constant>(AI->getArraySize()))
+ if (!allocaWouldBeStaticInEntry(AI))
continue;
// Keep track of the static allocas that we inline into the caller.
@@ -1635,7 +1642,7 @@ bool llvm::InlineFunction(CallSite CS, I
// Scan for the block of allocas that we can move over, and move them
// all at once.
while (isa<AllocaInst>(I) &&
- isa<Constant>(cast<AllocaInst>(I)->getArraySize())) {
+ allocaWouldBeStaticInEntry(cast<AllocaInst>(I))) {
IFI.StaticAllocas.push_back(cast<AllocaInst>(I));
++I;
}
Added: llvm/trunk/test/Transforms/Inline/inalloca-not-static.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/Inline/inalloca-not-static.ll?rev=278571&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/Inline/inalloca-not-static.ll (added)
+++ llvm/trunk/test/Transforms/Inline/inalloca-not-static.ll Fri Aug 12 17:23:04 2016
@@ -0,0 +1,63 @@
+; RUN: opt -always-inline -S < %s | FileCheck %s
+
+; We used to misclassify inalloca as a static alloca in the inliner. This only
+; arose with for alwaysinline functions, because the normal inliner refuses to
+; inline such things.
+
+; Generated using this C++ source:
+; struct Foo {
+; Foo();
+; Foo(const Foo &o);
+; ~Foo();
+; int a;
+; };
+; __forceinline void h(Foo o) {}
+; __forceinline void g() { h(Foo()); }
+; void f() { g(); }
+
+; ModuleID = 't.cpp'
+source_filename = "t.cpp"
+target datalayout = "e-m:x-p:32:32-i64:64-f80:32-n8:16:32-a:0:32-S32"
+target triple = "i386-pc-windows-msvc19.0.24210"
+
+%struct.Foo = type { i32 }
+
+declare i8* @llvm.stacksave()
+declare void @llvm.stackrestore(i8*)
+
+declare x86_thiscallcc %struct.Foo* @"\01??0Foo@@QAE at XZ"(%struct.Foo* returned) unnamed_addr
+declare x86_thiscallcc void @"\01??1Foo@@QAE at XZ"(%struct.Foo*) unnamed_addr
+
+define void @f() {
+entry:
+ call void @g()
+ ret void
+}
+
+define internal void @g() alwaysinline {
+entry:
+ %inalloca.save = call i8* @llvm.stacksave()
+ %argmem = alloca inalloca <{ %struct.Foo }>, align 4
+ %0 = getelementptr inbounds <{ %struct.Foo }>, <{ %struct.Foo }>* %argmem, i32 0, i32 0
+ %call = call x86_thiscallcc %struct.Foo* @"\01??0Foo@@QAE at XZ"(%struct.Foo* %0)
+ call void @h(<{ %struct.Foo }>* inalloca %argmem)
+ call void @llvm.stackrestore(i8* %inalloca.save)
+ ret void
+}
+
+; Function Attrs: alwaysinline inlinehint nounwind
+define internal void @h(<{ %struct.Foo }>* inalloca) alwaysinline {
+entry:
+ %o = getelementptr inbounds <{ %struct.Foo }>, <{ %struct.Foo }>* %0, i32 0, i32 0
+ call x86_thiscallcc void @"\01??1Foo@@QAE at XZ"(%struct.Foo* %o)
+ ret void
+}
+
+; CHECK: define void @f()
+; CHECK: %inalloca.save.i = call i8* @llvm.stacksave()
+; CHECK: alloca inalloca <{ %struct.Foo }>, align 4
+; CHECK: %call.i = call x86_thiscallcc %struct.Foo* @"\01??0Foo@@QAE at XZ"(%struct.Foo* %0)
+; CHECK: %o.i.i = getelementptr inbounds <{ %struct.Foo }>, <{ %struct.Foo }>* %argmem.i, i32 0, i32 0
+; CHECK: call x86_thiscallcc void @"\01??1Foo@@QAE at XZ"(%struct.Foo* %o.i.i)
+; CHECK: call void @llvm.stackrestore(i8* %inalloca.save.i)
+; CHECK: ret void
More information about the llvm-commits
mailing list